Clock



May 16, 1939.

"EW G L- WA 04 a l TgEY Patented May 16, 1939 UNITED STATES PATENT OFFICE CLOCK Application April 1, 1935, Serial No. 14,024

8 Claims.

This invention relates to a clock for indicating elapsed time intervals.

Among the objects of the invention are to provide a clock which will indicate, at the end of a time interval, both the numerical value of the time at the start of the interval and at the end thereof; to provide a clock, the hands of which may be stopped to indicate the start of a time interval and which, at the end of said interval, may be made to automatically set itself to indicate the correct time; to provide a clock, of the character described, which will re-set itself to the correct time at the end of an elapsed time interval without the hands thereof being required to traverse more than 180 degrees of arc; to provide a clock provided with electrically actuated means which may be connected to electrically operated fire systems to indicate the elapsed time that fire apparatus is away from its station; and to provide a simple and accurate means for performing the functions of the character described.

Referring to the drawings:

Figure 1 is a horizontal sectional view of a clock embodying the principles of the invention. The plane of section is indicated by the line of Figure 2.

Figure 2 is a vertical sectional view of the clock shown in Figure 1 and the plane of section is indicated by the line 2-2 of the latter figure.

Figure 3 is a view similar to Figure 2 but showing the mechanism in a different operating position. The preferred form of the invention chosen for illustration is a clock which may be used in fire stations to indicate the elapsed time that the apparatus is away from the station.

In detail a cylindrical casing 4 is provided having an end plate 5 forming a closure for the back thereof, and an end plate 6, having a central aperture therein in which is mounted a sheet of glass 1, forming a closure for the front thereof.

A pair of spaced plates 8 and 9 are mounted within the casing on the rods I0, and the latter of these plates has, disposed on the surface thereof facing the glass I, a dial II which may carry the usual indicia and numerals found on the ordinary clock dial.

Secured to the plate 8 is a synchronous electric motor l2, of the self-starting type commonly used in electric clocks, whose pinion I3 projects through an aperture formed in the center of the plate. A stub shaft I4 is secured to the plate 8 in spaced relationship with the axis of the pinion I3 and has journaled thereon a gear I5, which meshes with the pinion |3, and a pinion I6 fixed thereto which meshes with a gear I'I disposed in axial alinement with the pinion l3. The gear I1 is freely journaled on a sleeve I8 which extends, at one end thereof, beyond the face of a pinion l9, which is fixed thereto, and a friction washer 20 is disposed between the gear and the pinion so as to permit relative rotation therebetween.

The lower end of the sleeve is provided with a pair of spaced heart-shaped cams 2|, whose lobes are diametrically opposed as shown in Figure 2. The peripheries of these cams are adapted to engage rollers 22 carried at the ends of arms 23 which are pivotally mounted on a disk 24 disposed in axial alinement with, and spaced from the end of, the sleeve l8. Torsion springs 25 are provided for each arm 23 so as to resiliently urge the rollers 22 into engagement with the peripheries of the cams 2|. The disk 24 is mounted on a shaft 26, which projects through the plate 9 and the dial I0, and is provided with a pointer or hand 21 which is adapted to sweep over the edge of the dial in cooperative relationship with the indicia thereon. The arrangement of the parts, and the ratio of the gearing, just described is such that the hand 21 is driven by the motor I2 so as to complete one revolution in one hour.

A second shaft 28 is provided journaled on the plate 8 and is disposed in spaced parallel relationship with the axis of rotation of the train of members forming the drive for the hand 21, and secured for rotation with the shaft 28 is a large gear 29 which meshes with the pinion IS. The shaft 28 is also provided with cams 30, similar to the cams 2| in form and arrangement, and similar arms 3| provided with rollers 32 which bear against the peripheries of the cams are mounted on a disk 33 which is secured on a sleeve 34 mounted for rotation on the plate 9. A pair of gears 35 are provided, one of which is secured for rotation with the sleeve 34 and the other of which is secured to a sleeve 36 which is journaled on the shaft 26 and carries a hand 31, which, like the hand 21 is adapted to move over the surface of the dial II in cooperative relationship with the indicia thereon. The ratios of the gearing, and the arrangement of the parts in this last described train of parts is such that the hand 31 will complete one revolution over the face of the dial in the period of 12 hours.

From the description thus far, it will be seen that the mechanism will function to indicate time as does the ordinary clock and although the positive drive from the motor to each hand is interrupted by the resilient connection contained in the cams 2| and 30 and the arms 23 and 3|, the small amount of friction to be overcome and the pressure of the rollers against the cam peripheries is such that the motor will drive the hands without being forced out of synchronism therewith.

Means are provided for holding the hands against rotation while permitting continued rotation of the motor. Located between the disks 24 and 33 and the gears 35, and disposed in a plane parallel therewith, is a slide 38, having an offset portion 39 formed at one end thereof, to which is attached a rod 46, which projects through the casing 4 to the exterior thereof, and is provided at its end with a knob 4|. A spring 42 is disosed between the slide 38 and the casing 4 so as to resiliently urge the slide upwardly. The slide is provided with alined guide slots 43 and 44 which engage, respectively, screws 45 and 46 secured to the plate 9.

It will thus be seen that the slide may be shifted longitudinally by reciprocation of the rod 40, and will, under the influence of the spring 42, return to its normal upper position, as shown in Figure 3, when the rod is released.

Secured by, and concentric with the screw 45 is a fixed collar il provided with a radially extending slot in which is secured a pair of parallel resilient members 48. These members extend downwardly to a position adjacent the peripheries of the disks 24 and 33 and are provided at this point with outwardly turned portions which are directed toward the disks. Secured to the slide is a wedge shaped stud 49 which, as shown in Figure 3, is adapted to occupy a normal position slightly spaced from the free ends of the resilient members 48, and, as shown in Figure 2, is adapted to assume a position between the ends thereof, when the slide is moved upwardly, so as to spread the members and cause the ends thereof to engage the peripheries of the disks. To facilitate this engagement the peripheries of the disks are provided with serrations 50 in which the ends of the members 48 are adapted to seat.

It will thus be seen that while the slide 38 is in the position shown in Figure 3, the disks 24 and 33 are free to rotate with the motor l2 and consequently permit the hands 21 and 3'! to be moved over the surface of the dial in synchronism with the motor to indicate time thereon. However, when the slide is moved upwardly to cause the stud 49 to spread the ends of the resilient members 48 and cause the latter to engage the peripheries of the disks 24 and 33 the latter, and also the hands, are locked against rotation although, due to the resilient connection between the cams, which are positively connected with the motor, and the disks, the motor is permitted to continue its rotation in synchronism with time. Continued rotation of the motor will cause the cams to rotate relative to the disks and, as a result, the rollers on each arm 23 and 3| will travel along the peripheries of the cams. It will be seen therefore that if, after a time, the disks are released from the members 48, the pressure of the rollers against the cams caused by the torsion springs will cause the rollers to seek the lowest portion of the cams, that indicated in Figure 2, with the result that the disks will be rotated at an accelerated rate and will catch up with the rotating cams and thereby restore synchronism between the parts. It will be obvious also that, since the hands are fixed for rotation with the disks the former will be moved over the dial to assume positions indicating the correct time.

Means are provided for electrically actuating the locking means for the disks. The present invention, in the embodiment shown in the drawings, finds use in fire stations, or other similar places, where electrically operated alarms are used. A solenoid i is secured to the plate 9 in a position spaced from the upper end of the slide 38 and axially transverse with the direction of movement thereof. The solenoid is provided with the usual iron core which, when magnetized by the windings of the coil, is adapted to hold the end 52 of an arm 53 in engagement therewith. The arm is pivotally mounted on the screw and is provided with a lug 5 which carries a pin 55 which is normally adapted to lie above a ledge 55 formed in a widened portion of the upper end of the slot 43. A spring 5? having one end thereof connected to the arm 53 and the other end thereof secured to the plate 9 is provided for swinging the arm outwardly upon de-energization of the solenoid winding. It will be seen that the pin 55 engaging the ledge 55 will hold the stud 49 in spaced normal relationship with the ends of the members 48 as long as the arm 53 remains in its upright position.

Most of the fire alarms in present use are operated on the so-called hot system, that is, current is flowing through the apparatus at all times except at the instant that an alarm is turned in, when the circuit is broken which actuates apparatus for indicating or sounding the alarm. It will be seen therefore that, if the clock of the present invention be connected to one of these alarm systems, the solenoid 5! will be constantly energized and will, as stated above, maintain the parts, including the stud 49, in normal positions so that the clock may perform its normal function of indicating time. However, as soon as an alarm is turned in, thereby breaking the circuit to the solenoid 5|, the latter will be de-energized which will permit the arm 53, under the influence of the spring 51, to swing outwardly thereby moving the pin 55 off the ledge 56 and into the slot 43, as shown in Figure 2, whereupon the slide will be snapped upwardly by the spring 42 causing the stud to spread the ends of the members 58 and lock the hands of the clock against further rotation. The hands will therefore be stopped the instant the alarm is turned in.

When the fire apparatus returns to its station it is desirable for the oiiicer in charge, in order to make a report to his superiors and as a matter of record, to know just how long the apparatus was away from the station. This he may ascertain by noting the time at which the hands of the clock were stopped, which occurred when the alarm was turned in, and by pulling downwardly on the knob 4| he releases the hands and, as was explained above, this restores the hands to positions indicating the correct time whereupon, by noting this, he may readily determine the elapsed time interval.

It will be noted that when the arm 53 was released, by opening of the solenoid circuit, the pin 55 entered the slot thereby locking the arm 53 against rettuning to its normal upright posi tion, when the circuit was restored, and thereby possibly releasing the disks, resetting the clock, and obliterating the record of the time that the alarm was turned in as indicated by the locked hands.

Means are provided for restoring the mechanism to its normal operating condition. The enlarged upper end of the slot 43 is provided with a sloping side wall 58 which, as will best be seen in Figure 2, engages the pin 55 during the downward movement of the slide, to re-set the clock,

and causes the arm 53 to be swung inwardly until the end thereof enters the portion of the magnetic field having sufficient fiux intensity as to attract the end of the arm and cause it to adhere to the solenoid core. The arm is thus held in its upright position, the pin 55 is positioned in contact with the ledge 56, and the stud 49 is held out of engagement with the members 48, as is shown in Figure 3, until the next alarm is turned in, whereupon the solenoid circuit will be broken and the cycle of operations described above will be repeated.

It will be observed that the movement of the hands from any position, in which they may be locked, to a position indicating the correct time when they are released, will not require movement thereof, through more than 180 degrees of arc. Let us suppose, for purposes of illustration, that the positions of the cams 2| and the disk 24 shown in Figure 2, correspond to the position of the minute hand indicating the numeral I2 on a clock dial superposed above the figure and that the direction of rotation of the parts is clockwise. It will be seen that, with the disk locked against rotation, the cam will continue rotating and the roller 22 will move outwardly as the lower peripheral half A of the cam passes thereunder. If, during movement of the cam through the portion A the disk is released the latter will rotate clockwise until the roller 22 again rests at the lowest point of the cam which may be, at that time, located at any position of rotation corresponding to the arc between the numerals l2 and 6 on the dial.

If the rotation of the cam exceeds 180 degrees, and the roller 22 passes over the lobe of the cam onto the peripheral portion B thereof, release of the disk will cause it to rotate counter-clockwise and move the hand from the numeral l2 to a position on the dial between the latter numeral and the numeral 6 depending upon the amount of the portion B of the cam which had passed under the roller in excess of the 180 degrees of arc represented by the portion A of the cam. It is thus possible, by means of the .arrangement of parts just described, to reset the clock to the correct time in the shortest possible time.

Since there is a possibility that a condition will obtain where the disk may be released with the rollers positioned exactly at the center of the cam nodes, and therefore the springs will be incapable of returning the rollers to their normal positions, means are provided, operable with the resetting mechanism for overcoming this objectionable feature. A pair of resilient fingers 59 are provided secured to the slide adjacent the upper end thereof so that their free ends are disposed in spaced relationship adjacent the peripheries of the disks. If, as mentioned above, the cams happen to stop on dead center, downward movement of the slide to manually reset the mechanism, as already explained, will cause the ends of the fingers to move into engagement with the serrated peripheries of the disks and impart thereto sufficient rotation to cause the cams to move relative to the rollers whereupon the springs Will urge the rollers to assume their normal positions. After thus imparting movement to the disks, the ends of the fingers will, under the influence of the spring 42, assume positions spaced from the disk peripheries, as shown in Figure 3, when the rod 40 is released.

To provide for manual setting of the hands, should for any reason the relationship thereof with the dial indicia become incorrect, a shaft 60, provided with a knob 6|, is journaled in the case 4 and is provided with a bevel gear 62 which meshes with a corresponding gear 63 carried on a short shaft 64 which carries a pinion meshing with the teeth of the large gear 29. Rotation of the shaft 60 will cause rotation of both trains of parts connected with the hands and thereby permit setting of the latter to indicate the correct time.

Having thus described my invention it will be seen that such a clock as the one disclosed herein may be used for accurately indicating, numerically, the extent of time intervals such as the length of time that fire or police vehicles are away from their stations, the time required for performing jobs, or portions thereof, in factories, or for many like purposes.

What we claim is:

1. The combination with a clock comprising a frame, a pair of drive shafts journaled on said frame, a motor mounted on said frame and connected to each of said shafts to drive said shafts at constant speed, a dial graduated in units of time, a pair of driven shafts rotatably connected with said drive shafts, indicators mounted for" thereof, said means comprising disks mounted for rotation with each of said driven shafts, each of said disks having serrations formed on the periphery thereof, a pair of fixed resilient arms mounted on said frame and disposed adjacent said disks, said arms having outwardly turned ends for engaging the serrations of said means for moving the ends of said arms into engagement with said disks comprising a slide movably mounted on said frame, a pin mounted on said slide having opposed sloping faces engageabie with said arms for forcing the ends thereof outwardly into engagement with the serrations of said disks when said slide is moved, means urging the movement of said slide to engage said pin and arms, means movably mounted on said frame for holding said slide to prevent movement of said pin into engagement with said arms, means for releasing said slide to permit engagement of said pin with said arms, and means for resiliently connecting said drive and driven shafts for rotation together and for permitting continued rotation of said drive shafts while said driven shafts are held against rotation, said means comprising a pair of opposed heart-shaped cams on each of said drive shafts, arms pivotally mounted on said disks naving rollers at the free ends thereof, and resilient means disposed between said arms and said disks for urging said rollers into engagement with the peripheries of said cams.

2. The combination with a clock comprising a frame, a pair of drive shafts journaled on said frame, a motor mounted on said frame and connected to each of said shafts to drive said shafts at constant speed, a dial graduated in units of time, a pair of driven shafts rotatably connected with said drive shafts, indicators mounted for rotation with each of said driven shafts and movable over the face of said dial to indicate time values thereon, of means for connecting said indicators to said frame for preventing movement thereof, said means comprising disks mounted for rotation with each of said driven shafts, each of said disks having serrations formed on the periphery thereof, a pair of fixed resilient arms mounted on said frame and disposed adjacent said disks,

said arms having outwardly turned ends for engaging the serrations of said disks, means for moving the ends of said arms into engagement with said disks comprising a slide movably mounted on said frame, resilient means for moving said slide in one direction, a pin mounted on said slide having opposed sloping faces engageable with said arms for forcing the ends thereof outwardly into engagement with the serrations of said disks when said slide is moved by said resilient means, means movably mounted on said frame for holding said slide to prevent movement of said pin into engagement with said arms, means for releasing said slide to permit engagement of said pin with said arms, and means for resiliently connecting said drive and driven shafts for rotation together and for permitting continued rotation of said drive shafts while said driven shafts are held against rotation, said means comprising a pair of opposed heart-shaped cams on each of said drive shafts, arms pivotally mounted on said disks having rollers at the free ends thereof, and resilient means disposed between said arms and said disks for urging said rollers into engagement with the peripheries of said cams.

3. The combination with a clock comprising a frame, a pair of drive shafts journaled on said frame, a motor mounted on said frame and connected to each of said shafts to drive said shafts at constant speed, a dial graduated in units of time, a pair of driven shafts rotatably connected with said drive shafts, indicators mounted for rotation with each of said driven shafts and movable over the face of said dial to indicate time values thereon, of means for connecting said indicators to said frame for preventing movement thereof, said means comprising disks mounted for rotation with each of said driven shafts, each of said disks having serrations formed on the periphthereof, a pair of fixed resilient arms mounted on said frame and disposed adjacent said disks, said arms having outwardly turned ends for engaging the serrations of said disks, means for moving the ends of said arms into engagement with said disks comprising a slide movably mounted on said frame, a pin mounted on said slide having opposed sloping faces engageable with said arms for forcing the ends thereof outwardly into engagement with the serrations of said disks when said slide is moved, means urging the movement of said slide to engage said pin and arms, means movably mounted on said frame for holding said slide to prevent movement of said pin into engagement with said arms, said means comprising a lever pivotally mounted on said frame adjacent said slide, a lug on said lever engageable with said slide for preventing movement thereof to move said pin into engagement with said arms, electromagnetic means for holding said lug in engagement with said slide, resilient means for withdrawing said lug from engagement with said slide upon de-energization of said electro-magnetic means, and means for resiliently connecting said drive and driven shafts for rotation together and for permitting continued rotation of said drive shafts While said driven shafts are held against rotation, said means comprising a pair of opposed heart-shaped cams on each of said drive shafts, arms pivotally mounted on said disks having rollers at the free ends thereof, and resilient means disposed between said arms and said disks for urging said rollers into engagement with the peripheries of said cams.

4. The combination with a clock comprising a frame, a pair of drive shafts journaled on said frame, a motor mounted on said frame and connected to each of said shafts to drive said shafts at constant speed, a dial graduated in units of time, a pair of driven shafts rotatably connected with said drive shafts, indicators mounted for rotation with each of said driven shafts and movable over the face of said dial to indicate time values thereon, of means for connecting said indicators to said frame for preventing movement thereof, said means comprising disks mounted for rotation with each of said driven shafts, each of said disks having serrations formed on the periphery thereof, a pair of fixed resilient arms mounted on said frame and disposed adjacent said disks, said arms having outwardly turned ends for engaging the serrations of said disks, means for moving the ends of said arms into engagement with said disks com prising a slide movably mounted on said frame, a pin mounted on said slide having opposed sloping faces engageable with said arms for forcing the ends thereof outwardly into engagement with the serrations of said disks when said slide is moved, means urging the movement of said slide to en gage said pin and arms, means movably mounted on said frame for holding said slide to prevent movement of said pin into engagement with said arms, said means comprising a lever pivotally mounted on said frame adjacent said slide, a lug on said lever engageabie with said slid for venting movement thereof to move engagement with said arms, electrcunagnetie means for holding said lever to position said lug in engagement with said slide, resilient means for withdrawing said lever from said electro-magnetic means and said lug from engagement with said slide upon deenergization of said e1ectromagnetic means, means operable upon movement of said slide in the other direction for returning said lever to its position to be held by eiectromagnetic means, and means for resiliently connecting said drive and driven shafts for rotation together and for permitting continued rotation of said drive shafts while said driven shafts are held against rotation, said means comprising a pair of opposed heart-shaped cams on each of said drive shafts, arms pivotally mounted on said disks having rollers at the free ends thereof, and resilient means disposed between said arms and said disks for urging said rollers into engagement with the peripheries of said cams.

5. The combination with a clock comprising a frame, a pair of drive shafts journaled on said frame, a motor mounted on said frame and connected to each of said shafts to drive said shafts at constant speed, a dial graduated in units of time, a pair of driven shafts rotatably connected with said drive shafts, indicators mounted for rotation with each of said driven shafts and movable over the face of said dial to indicate time values thereon, of means for connecting said indicators to said frame for preventing movement thereof, said means comprising disks mounted for rotation with each of said driven shafts, each of said disks having serrations formed on the periphery thereof, a pair of fixed resilient arms mounted on said frame and disposed adjacent said disks,

said arms having outwardly turned ends for engaging the serrations of said disks, means for moving the ends of said arms into engagement with said disks comprising a slide movably mounted on said frame, a pin mounted on. said slide having opposed sloping faces engageable with said arms for forcing the ends thereof out-- wardly into engagement with the serrations of saiddisks when said slide is moved, means urging the movement of said slide to engage said pin and arms, means movably mounted on said frame for holding said slide to prevent movement of said pin into engagement with said arms, said means comprising a lever pivotally mounted on said frame adjacent said slide, a lug on said level engageable with said slide for preventing movement thereof to move said pin into engagement with said arms, electro-magnetic means for holding said lever to position said lug in engagement with said slide, resilient means for withdrawing said lever from said electro-magnetic means and said lug from engagement with said slide upon deenergization of said electro-magnetic means, means operable upon movement of said slide in the other direction for returning said lever to its position to be held by said electro-magnetic means, said means comprising a portion of said slide having a sloping surface thereon for engaging said lug when said slide is moved, and means for resiliently connecting said drive and driven shafts for rotation together and for permitting continued rotation of said drive shafts while said driven shafts are held against rotation, said means comprising a pair of opposed heart-shaped cams on each of said drive shafts, arms pivotally mounted on said disks having rollers at the free ends thereof, and resilient means disposed between said arms and said disks for urging said rollers into engagement with the peripheries of said cams.

6. The combination with a clock comprising a frame, a pair of drive shafts journaled on said frame, a motor mounted on said frame and connected to each of said shafts to drive said shafts at constant speed, a dial graduated in units of time, a pair of driven shafts rotatably connected with said drive shafts, indicators mounted for rotation with each of said driven shafts and movable over the face of said dial to indicate time values thereon, of means for connecting said indicators to said frame for preventing movement thereof, said means comprising disks mounted for rotation with each of said driven shafts, each of said disks having serrations formed on the periphery thereof, a pair of fixed resilient arms mounted on said frame and disposed adjacent said disks, said arms having outwardly turned ends for engaging the serrations of said disks, means for moving the ends of said arms into engagement with said disks comprising a slide movably mounted on said frame, a pin mounted on said slide having opposed sloping faces engageable with said arms for forcing the ends thereof outwardly into engagement with the serrations of said disks when said slide is moved, means urging the movement of said slide to engage said pin and arms, means movably mounted on said frame for holding said slide to prevent movement of said pin into engagement with said arms, said means comprising a lever pivotally mounted on said frame adjacent said slide, a lug on said lever engageable with said slide for preventing movement thereof to move said pin into engagement with said arms, electro-magnetic means for holding said lever to position said lug in engagement with said slide, resilient means for withdrawing said lever from said electro-magnetic means and said lug from engagement with said slide upon de-energization of said electro-magnetic means, means operable upon movement of said slide in the other direction for returning said lever to its position to be held by said electro-magnetic means, resilient means on said slide for engaging said disks and imparting rotary motion thereto when the slide is moved in said other direction, and means for resiliently connecting said drive and driven shafts for rotation together and for permitting continued rota tion of said drive shafts while said driven shafts are held against rotation, said means comprising a pair of opposed heart-shaped cams on each of said drive shafts, arms pivotally mounted on said disks having rollers at the free ends thereof, and

resilient means disposed between said arms and said disks for urging said rollers into engagement With the peripheries of said cams.

7. A time indicating device comprising driving means, first and second time indicating members operable thereby, elastic driving connections, having oppositely rotating driven elements, between each of said members and said driving means, and a member engageable between said elements to lock said indicating members.

8. A time indicating device comprising, a synchronous electric motor, hour and minute hands, separate elastic connection means connecting said hands and motor and permitting of the stopping of said hands during the continuous movement of said motor and eifective upon release of said hands to quickly advance the same to coincide with the advanced movement of said motor during the period which the hands were so held, means for simultaneously locking said hands, and electrically operated means for actuating said last named means.

MAURICE McLELLAND. CORNELIUS P. DE JONGE. 

